Telitacicept cuts eGFR decline risk 89% in Phase 3 IgAN trial
Vor Bio has reported final two-year results from the Phase 3 TELIGAN trial of telitacicept in IgA nephropathy, showing the drug near-halted the decline in kidney function that defines the condition's natural history. The data were presented in an oral session at the American Society of Nephrology Kidney Week 2026 in Denver on 22 October.
The headline finding was an annualised estimated glomerular filtration rate (eGFR) slope of -0.6 mL/min/1.73 m²/year in the telitacicept group against -5.7 mL/min/1.73 m²/year in the placebo group over 104 weeks, a between-group difference of 5.1 mL/min/1.73 m²/year (p<0.001). Telitacicept was also associated with an 89% lower risk of a confirmed 30% eGFR decline and an 81% lower risk of a confirmed 40% decline. No patient in the treatment arm reached a composite kidney failure endpoint, compared with five in the placebo arm, two of whom required dialysis.
Trial design and proteinuria data
TELIGAN enrolled 318 adults with biopsy-confirmed IgAN on stable background therapy, randomised 1:1 to telitacicept 240 mg or placebo. Dosing was once weekly through week 39 (Stage A), then shifted to every-other-week administration from week 40 through week 104 (Stage B). The Stage B primary endpoint was annualised eGFR slope through week 104, and the trial met it with statistical significance.
Proteinuria endpoints were consistent. At week 104, the 24-hour urine protein-to-creatinine ratio had fallen 60.3% from baseline in treated patients against a 0.9% increase in the placebo group. Some 44% of telitacicept-treated patients achieved a 24h-UPCR below 0.5 g/g at week 104, compared with 8.2% on placebo. Reductions were maintained after the switch to every-other-week dosing, a finding that may support flexible real-world administration. Serum galactose-deficient IgA1, a pathogenic driver of the condition, fell 47.79% from baseline with telitacicept and rose 19.06% with placebo, consistent with the drug's dual BAFF/APRIL mechanism.
On safety, treatment-emergent adverse events occurred in 95% of the telitacicept group versus 89.3% in the placebo group, a difference partly attributable to injection-site reactions (56% versus 18.9%, mostly mild to moderate). Notably, serious adverse events were lower in the treated arm (8.2% versus 18.2%), as were serious infections (1.9% versus 4.4%).
Market context and regulatory path
IgAN has become one of the most contested nephrology indications of the mid-2020s. Sparsentan (Travere Therapeutics) received full FDA approval in 2024, and iptacopan (Novartis) gained approval in 2025 targeting the complement pathway. Atrasentan (Chinook/Novartis) has also reported positive Phase 3 data. Telitacicept's dual BAFF/APRIL mechanism is distinct from these approved agents, which raises the possibility of combination use or differentiated positioning in patients who progress despite existing therapy.
Telitacicept received conditional approval in China in June 2026 for proteinuria reduction in primary IgAN. The TELIGAN trial was conducted solely in China by collaborator RemeGen, and Vor Bio's own disclosures acknowledge that regulators outside China, including the FDA and EMA, may not accept data generated in a single-country population. That extrapolation question is the central regulatory risk for the ex-Greater China programme, where Vor Bio holds exclusive rights. The company said it is advancing global Phase 3 trials in myasthenia gravis and Sjögren's disease in parallel, suggesting it is building a broader regulatory dossier for its BAFF/APRIL platform.
Jean-Paul Kress, chairman and chief executive of Vor Bio, said the two-year findings "reinforce the clinical potential of telitacicept" and add to evidence supporting dual BAFF/APRIL inhibition across autoantibody-driven diseases.